ABSTRACT
The analysis of the first, second and third harmonic electro-optical responses (EORs) have been performed for planar samples of the liquid crystal (LC) having a broad temperature range of the phase. It demonstrated strong dependence on the angle between the polariser and the smectic layers normal. The comparison of these measurements for the smectic LC cells with both homogeneously and random orientation of the director agreed with results of the performed theoretical considerations based on the deformation of both the helix and the indicatrix under applied electric field. For the homogeneously aligned cell, the electro-optical effects are dominated by the strong linear process – in contrast to the unaligned cell, where the second-order EOR is important. The study of angular dependence of the nonlinear EOR allowed for easy separation of linear and nonlinear effects.
Graphical Abstract
Disclosure statement
No potential conflict of interest was reported by the authors.